Abstract # 3176 Poster # 85:

THE INFLUENCE OF AGE AND DOMINANCE STATUS ON FECAL TESTOSTERONE, DIHYDROTESTOSTERONE, AND CORTISOL EXCRETION IN MALE WHITE-FACED CAPUCHIN MONKEYS (CEBUS CAPUCINUS) IN SANTA ROSA NATIONAL PARK, COSTA RICA.

In male primates, developmental stages involve an increase in androgen production and can indicate the start of reproductive maturation. However, in our recent analysis of androgen levels in adult male white-faced capuchins in Santa Rosa, Costa Rica we found that alpha males have significantly higher levels than subordinates. Here we expand this research and compare testosterone (T), dihydrotestosterone (DHT), and cortisol levels across male age classes and dominance status (infants, small immatures, large immatures, subadults, subordinate and alpha adults). Fecal samples (N=163) were collected opportunistically from males (N=37) residing in three long-term study groups between May-July 2010. T, DHT, and cortisol levels were determined for each sample. Using the average hormone value for each individual, we found that mean ranks of male T level differed significantly across age and adult dominance status categories (Kruskal-Wallis: X2= 15.944, df=5, p=0.007). Our pairwise comparisons found that alpha males have higher mean T ranks than large and small immature males (Large Immatures: 23.056, n=37, p=0.021; Small Immatures: 21.650, n=37, p = 0.036), but there were no differences across the other categories of analysis. The mean ranks of DHT, DHT:T ratio, and cortisol did not differ across age categories. Results provide valuable insight regarding pubertal development in this species, and indicate that no single age or rank category is associated with relatively greater social or physiological stress.